/*write.c*/
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define MAXSIZE

int main(void)
{
    int i,fd,size,len;
    char *buf = "Hello！I am writing to this file！";
    char buf_r[10];
    len = strlen(buf);
    // 首先调用open函数，并指定相应的权限
    if((fd = open("/tmp/hello.c", O_CREAT|O_TRUNC|O_RDWR,0666)) < 0)
    {
        perror("open:");
        exit(1);
    }
    else
        printf("open file:hello.c %d \n",fd);
    if((size = write(fd, buf, len)) < 0)
    {
        perror("write:");
        exit(1);
    }
    else
        printf("Wirte:%s\n",buf);
    // 调用lseek函数将文件指针移动到文件起始，并读取文件中的10个字节
    lseek(fd, 0, SEEK_SET);
    if ((size = read(fd, buf_r, 10)) < 0)
    {
        perror("read:");
        exit(1);
    }
    else
        printf("read from file:%s\n",buf_r);
    if(close(fd) < 0)
    {
        perror("close:");
        exit(1);
    }
    else
        printf("Close hello.c\n");
    exit(0);
}